What kind of desktop should I buy?

Hello!

I am not sure if this is the right place to post, but here it goes. I need help on which desktop to buy. I am a PhD student so I really be writing a ton! I also use LateX quite a bit. I don’t really do too much other than that. However, I do have dyslexia so the bigger the screen the better it is for me to read. I also get migraines if I am staring too long at certain (it seems cheaper screens). I do not have this problem with apples 4K or 5k Retina display. The obvious solution here is to just buy an iMac. However, all I really need is a reliable computer to write papers on (and other academic related things) that doesn’t give me a migraine. My thought is that an iMac will work, but I may not need something that expensive. I can comfortably afford something around $1000, thus an iMac is stretching my budget. Any suggestions would be great! A preliminary search of the options is pretty overwhelming.